Media services such as Internet video streaming are becoming increasingly popular. Typical Internet video streaming uses streaming protocols such as MPEG DASH or HTTP Live Streaming HLS that use the Hyper Text Transfer Protocol (HTTP) as the primary transport protocol. With more devices and formats becoming available, media is often converted to a personalized format before being delivered to a client. Contrary to traditional broadcasting, advertisements or formats can be fully personalized as contrary to TV broadcasting, each user receives data through their own Internet connection. This makes insertion or conversion of content in Internet video presentations for advertisement attractive and a large potential source of revenue. Example of conversion could be insertion, editing or re-encoding of content for personalization and or monetization. This is usually done to comply with user and or device needs for a media streaming presentation.
The Media industry uses many different formats such as those defined by the Moving Picture Experts Group (MPEG) and proprietary ones defined by companies such as Apple®, Microsoft® and Adobe®. Delivery of converted content to is useful for fitting content to different screen sizes and types, complying to protocol needs and/or matching user preferences.
The Unified Remix Solution and Unified Origin developed and sold by the Unified Streaming Platform, are examples of state of the art system convert media from one format to another format. For example the Unified Origin can be used to convert a media file into a streaming presentation such as based on protocols such as MPEG DASH, HTTP Live Streaming HLS. The Unified Remix solution is current state of the art for streaming of personalized and edited media content. This solution can create a remixed MPEG-4 meta-data file that references different media sources. This MPEG-4 meta-data file can then be used for streaming the content using Unified Origin.
Nevertheless, as different segments exist in the streaming manifest files the caching in the content delivery remains a problem. This is a large problem as content delivery networks typically use the URL as a cache key for storing content. Caching networks such as CDN's typically cache based on the name and location of the content item specified by the uniform resource locator string URL. For highly personalized playlists each of the segments will have different URL. From the outset of this text it is assumed that URL refers to a string locating or identifying a resource such as Uniform Resource Locator URL or Uniform Resource Indicator URI as defined in respective request for comments documents published by the Internet Engineering Task Force (IETF). The Unique URLs in personalized media presentations make delivering and caching this type of content challenging. This has triggered active academic and industry research.
The absence of a solution to this problem makes it very difficult to deploy cost efficient highly personalized video streaming using content delivery networks, hindering monetization of content in the best possible way. This problem also applies to converted content, including watermarked streams, personalized streams and many other type of personalized streams. An example of a recent research in this area was presented He et al. ACM MMSys 2018 in the paper entitled Watermarked Video Delivery: Traffic Reduction and CDN Management.
More and more converted and derived media is becoming available for delivery, caching and storing. Caching and delivering such content efficiently is becoming an increasingly important problem for the industry. Several research works addressed caching which is e.g. Y Jin et al Transactions on circuits and systems for video technology 2015, C. Liu patent application U.S. Pat. No. 8,977,704B2.